What is a Single Point of Failure (SPOF)?

Updated Apr 28, 2026

Short answer

Any component of a system that, if it fails, causes the entire system to stop functioning.

Deep explanation

Availability and Reliability are the cornerstones of production-grade systems. Any component of a system that, if it fails, causes the entire system to stop functioning. Ensuring high uptime requires both preventing failures and minimizing recovery time.

Real-world example

A website staying up during a traffic spike by using multiple servers.

Common mistakes

  • Assuming a system is reliable just because it is available (e.g., it's 'up' but returns errors).

Follow-up questions

  • How many minutes of downtime is 99.99% availability?

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